Right, got it going quite well on Mojave - UX580GE (6 core i9 / HD630 and 1050 Ti GPU) coffee lake.
After ages I found that the M.2 samsung 961 it came with doesn't play well and only booted in single user mode, the 970 plus I then got is the same, so a quick exchange to a standard 970 finally worked. The SMBIOS is the 15,1 and it works pretty natively following this guide. Uses the same CPU.
Not working is the egpu, TB3, trackpad (trackpad is some new interactive screen thing that operates as a 2nd monitor) and internal wifi/bluetooth. Not sure they will ever work.
The touchscreen weirdly works and I've got USB 3.1 with no issues. Sound was easy but the headphone jack stutters.
Issues I can probably fix in time is a kp on shutdown, kp at the end of a CC clone and other small issues related. Update Mojave via the about this mac / update worked, but got kp at the end and didn't clean up the install files. the install worked fine though.
I've attached clover folder and an io reg explorer file in case someone wants to take a look or use it as a base.
Oh, I pulled it apart already and put liquid metal for better cooling. It idles the same, 40deg - fan profiles are **** and don't start till about 60deg, but I got 1250 on cinebench - 25% better than without the liquid metal TIM
so there isn't too much throttling now.